Field of the Disclosure
The present subject matter relates generally to chemical testing of liquid samples and more specifically to optical test systems and methods for general purpose determination of chemical concentration in a liquid solution.
Description of Related Art
Chemical test paper strips are known for use in measuring chemical concentrations, such as pH, water hardness, and concentration of chlorine, ammonia, and many other chemical concentration levels in water and other liquids. Test strips are used in many industrial, medical and environmental applications. Typically, each test strip is delivered with a small color chart for the user to compare and estimate the resulting concentration of chemical in solution. For example, chlorine test strips use potassium iodide as an active ingredient. In the presence of an oxidant such as chlorine, iodide is converted to iodine which then binds to starch molecules in the strip and forms a blue colored complex. In a specific example, test strips of this type are used to verify the correct concentration of chlorine in the rinse water of commercial dish machines used in restaurants.